Woodworkers and finishers,
like you and me, are often interested in making colorants and
finishes at home, sometimes from common household products or
from simple chemical mixtures. This is a discussion of a few
selected recipes along with some of the science behind them.

Note
Most of the methods and recipes presented here are meant mostly
for fun. They are not really meant for production use because
they are sometimes slow and not necessarily inexpensive. However,
I do use pigmented waxes of my own making, every day. I also
use the homemade glazing stain (gilp).

The colors some of these homegrown
finishes produce are not very colorfast, either, compared with
modern dyes and pigments. There is a reason we use more modern
chemistry when we use modern finishes. The results, in general,
are far superior to materials and methods available 200 years
ago.

Pigments and Dyes
In woodworking, we use two primary types of colorants: pigments
and dyes.

Pigments are very small particles
that reflect colors. Because they are particles, they will actually
stop light from passing through, if there are enough of them.
Paint, which is opaque, is made from pigments. If you apply
paint to glass it will block the light coming through the glass.
Pigments are usually manufactured, but there are lots of natural
ones.
Red ochre, French gold ochre, and burnt sienna are all earth
pigments. These pigments were originally made from very finely
ground colored soils, soft rocks, soot, and charred bone. Most
pigments in current use are manufactured, but earth pigments
are still readily available.

Dyes are different from pigments.
They are not small particles, but are molecules, which are infinitely
smaller. If you completely dissolve a dye in water, light will
still pass through the water. This is because molecules of dye
do not block light, they absorb some colors and let others pass
on through. For example, woad, a plant product, is a natural
dye. Natural dyes are mostly derived from plant or animal sources.
Navajo Indians still use some vegetable dyes to color wool for
rugs and blankets. Other natural products like sheep urine or
shellfish exudates were also used. In case you're curious, sheep
urine makes a pale bluish color and it doesn't work on wood.
Generally speaking, most natural dyes produce very limited color
intensity. This is unlike the bright manmade dyes we commonly
use to color fabric and sometimes wood.

And please note - just because
something is a natural product does not mean that it is necessarily
non-toxic. For example, the pigment Paris green is based on
copper and is extremely poisonous. It's even used as rat and
bug poison. Natural does NOT equal safe, all the time. Be sure
to always wear protective gloves and eye protection, even if
you think what you are doing is fairly safe.

The other important note is
that some processes are not predictable. For example, you can
apply an iron and vinegar solution to oak and get very different
colors. They may range from silver gray to dark brown. Each
tree seems to react differently. You will need to experiment
on scrap first before you ever consider employing any of these
recipes as part of a finish on a real project.

You may also want to raise
the grain on the wood and sand very lightly first. This is because
a lot of treatments involve using water.

There are two ways to color
wood:
Alter chemicals already in the wood to make them behave like
a dye or add colorant to the wood surface. First, let's look
at ways to alter the chemicals (extractives) already present
in wood. Then we will look at some colorants.

Altering Wood: Sunburned
Wood
Many species of wood change color, quickly or slowly, when exposed
to direct sunlight. You can think of it as giving the wood a
case of sunburn, if you like. Cherry will darken substantially
in as little as 2 hours of direct exposure to sunlight. This
is the same darkening that occurs to cherry naturally, but much
more slowly, inside. This is a fast way to simulate old cherry.

Purpleheart turns brown but
does so much more rapidly in direct sun. White pine becomes
yellow-orange in two or three days of intense sun, in the same
way cherry darkens. Orange white pine is referred to as pumpkin
pine. Pumpkin pine is what you see in old furniture made from
white pine. Again, this is a way to get simulated aged wood.

In general, the action of ultraviolet
light on wood acts to move the natural color of the wood the
'other direction'. Walnut becomes tan, teak silver, and pine
yellow-orange. As a rule, dark woods fade, and pale woods gain
color. This is part of the esthetic value people place on antique
wood.

Since wood has only a small
amount of extractives present, the total possible amount of color
shift is usually pretty limited. More exposure to UV light does
not create proportionately more color change. There is always
an end point. For cherry, it is generally about 4-8 hours in
direct sunlight, for example. Sun exposure is not a practical
approach for coloring some species of wood like elm or ash, unless
you are very patient. Plus, any subsequent surfacing of the
wood removes the sunburned color because it is only skin deep
to start with. Leaving wood outside uncovered for long periods
also causes ultraviolet erosion of the wood. UV erosion will
rough up the surface as well. This means resurfacing may be
required, undoing the ageing effect.

Altering Wood: UV Damage
Note
Ultraviolet eroded wood surfaces do not hold either glue or finishes
as well as fresh wood. It very negatively affects exterior finish
lifetime if you apply finish over UV damaged wood surfaces.
The Forest Products Laboratory (part of the USDA) has published
several papers on the subject. What this means - it is good practice
to finish exterior wood before it sits around in the sun for
several days.

High temperature storage, maybe
in an attic in the summer, will also darken cherry wood over
a period of time. Heat also speeds color changes in many oily
tropical woods, like teak, rosewood, or zebrawood. Other species
like oak are generally unaffected.

Altering Wood: Tannins
Tannins are extractives that you can actively darken several
ways. You can also add tannins to wood to increase the total
color change effect.

Adding tannins is simple.
Get regular orange pekoe (Lipton's) or other dark tea. Steep
about 10 tea bags in 1 qt hot water. Put the bags into boiling
water, then turn off the heat and let it sit for about 2-3 hours.
Remove the bags, being sure to squeeze out liquid from each
bag. Apply an even coat of the tea-saturated water to any species
of wood. Wipe completely dry, then allow the wood to dry overnight.

Tea is high in tannins, plus
it also adds a small amount color. This tannin enhanced wood
reacts vigorously with iron acetate as described below. You
can use tea on woods that contain no tannins, and treat the surface
just like it was oak to start with. Adding a lot of dark tea
also creates an aged, slightly grungy look on species like willow
and elm. These species seem to get more color change from tea.
This, without any iron treatment.

Tannins react with metals like
iron. Soak a pad of fluffed-out, oil-free fine steel wool in
2 cups of clear vinegar at least overnight. To make oil-free
steel wool, rinse the steel wool in thinner, then let the steel
wool dry fully. Vinegar reacts with iron in the steel wool to
make iron acetate. Apply your vinegar solution to any tannin
bearing wood, like oak. Also, apply your iron solution to any
wood that has been treated with tea.

The resulting color usually
looks like aged oak. It ranges from a silvery gray to a dark
brown, depending on the amount of tannins present, the concentration
of iron acetate, and other factors. Iron salts applied to many
species has little or no effect, and now you see the reason why.
The quick way to see the effects of iron is to look at old construction
or old furniture where nails or iron hardware contacts the wood.
If you see dark zones around the nail or hinge, then the wood
species does react with iron to create color.

Altering Wood: Ammonia
Oak species also react with ammonia, turning a dark brown color.
Mission furniture was originally colored with a process known
as ammonia fuming. The odd thing about fuming is that the color
change is not very evident on dry, unfinished wood. The full
color change becomes apparent only after you apply a clear finish
like boiled linseed oil or varnish.

Traditional fuming of oak must
be done in specially constructed plastic tents with concentrated
ammonia (26%). This is EXTREMELY nasty stuff to handle. Consider
something else.

The something else is household
ammonia. You can achieve some darkening of oak by using soap-less
household ammonia, straight from the bottle. Do this ONLY in
a really well ventilated area with a fan blowing across the work
to push the ammonia fumes away from you and outside. Ammonia
fumes are horrible. Be careful. Simply apply the ammonia with
a rag or brush, let it stand until it has evaporated, then wash
the surface with very dilute vinegar. This neutralizes the ammonium
hydroxide left behind from the ammonia solution. Wash off with
plain water and let dry. This is messier than fuming but gives
some of the color. If you want to try fuming, Taunton Press
has published information on finishing practices, and one of
them is about fuming.

Altering Wood: Lye
Lye will darken cherry, giving the about same appearance or darker,
compared to what you get from direct sun exposure.

Dissolve 1 tsp of lye (Red
Devil works fine) in about 3 cups of cold water. Be aware that
lye solutions are caustic, and if they remain on wood for fairly
long periods of time it will result in damage to the wood surface,
making the wood appear fuzzy. One-half hour with dilute lye will
do no damage. However, stronger caustic solutions may break wood
fibers loose.

Leave the lye solution on the
wood only until you have good color, usually just a few minutes.
The color change happens faster in really warm temperatures.
Next, neutralize the surface with dilute vinegar, and finally,
wash with plain water. The color will continue to darken slightly
more for a few minutes, even though lye is no longer on the surface.
Longer exposure to lye will yield somewhat darker colors, up
to a point, then no further perceptible darkening occurs. This
process absolutely requires testing on scrap first.

Altering Wood: Household
Bleach
Household bleach like Clorox will remove mildew stains on raw
wood. It will lighten wood that has been dyed with commercial
wood dye. Complete dye reversal requires more powerful bleach,
like the "Part A" (hydrogen peroxide) found in two-part
wood bleach.

Household bleach will also
lighten some species of raw wood slightly, generally the darker
species like mahogany, walnut, and black or red oak. The amount
of lightening is fairly small. Inside, or in the shade, apply
liquid bleach with a rag, right out of the container, and let
it stand until it dries. No rinse is required unless you plan
on adding a commercial dye on top of the bleach. Consider using
bleach on oak if it looks somewhat variegated - dark and light
areas on one board. Bleach seems to even out this sort of problem
pretty well. This is because it seems to work more effectively
on the darker zones.

Altering Wood: Pharmacy
Chemicals
Potassium dichromate darkens wood. The effect is somewhat like
the browning of tannins with iron acetate. So, potassium dichromate
is sometimes used on low tannin wood species. Potassium dichromate
is toxic. Application is the same as with iron acetate, let
it dry, then wash it off. Mix about 1 tsp per quart of cold
water (or follow the label for "Bichromate of Potash")
for the working solution. Repeat the process until no further
darkening occurs. The reason for going to the end point is that
it isn't easy to get an intermediate color that is even.

You must wear gloves and protective
gear!

Potassium permanganate can
also be applied to wood species that are low in tannins. It
is toxic, as well as a powerful oxidant. Use it the same way
you use potassium dichromate.

Bichromate of potash (potassium
dichromate by another name) is available from www.garrettwade.com
and either chemical can be had through local pharmacies, depending
on local regulations.

Adding Colorants: Common
household colorants
Adding household dyeing agents or pigments to wood is generally
the safest and easiest method for coloring wood, if you want
to try non-standard procedures.

Strongly brewed coffee, applied
cold to wood, imparts a solid brown cast to most species of wood.
Let the coffee sit on the wood surface, with surface constantly
wet, for about 10-15 minutes, then wipe thoroughly. Let the surface
dry for several hours before applying any other finishes. Coffee
that has sat at high (180F +) temperature for long periods of
time or is several days old is oxidized and does not work well
as a colorant. Freshly brewed, cold coffee works the best.

Since the color extends only
a short distance into the wood, a protective clear coat, or even
paste wax is recommended over a coffee stain. One really nice
feature of coffee staining is that future coffee spills present
no problem. Coffee is somewhat lightfast, but will not do for
exterior use.

Fruit juices which are high
in anthocyanins (purple color in grape juice) will stain wood,
but the color pales rapidly to a tan or brown color. They are
not recommended for staining.

To get really bright colors,
food coloring works very well as a wood dye. The best substrate
is a wood that is close to white, like white pine. This allows
the color of the dye to show through more clearly without being
altered by amber tones in the wood.

This method produces non-toxic,
painfully bright colors for children's toys. Adding a clear
coat of spray lacquer will improve durability as well as prevent
color leakage onto children's hands. Clear lacquer is made from
nitrocellulose, the same stuff as cellophane, and is completely
edible when fully cured. Food colors are not lightfast, but will
last for several years. Red and yellow fade the fastest.

Food colors are available in
larger 4 oz jars, avoid the small plastic drop jars which are
too expensive for this kind of application. Mix the dye about
5-6 parts water to 1 part food coloring and flood the wood surface
for about five minutes. Work out of direct sunlight. Wipe the
surface repeatedly to remove any residual dye that has not gone
into the wood. After the surface dries overnight, attack it
once more with rags to remove any light powdering of color that
may remain.

To create secondary colors
like orange and purple, mix primary food colors, just like we
did back in first grade.

"Rit" brand fabric
dyes also work on wood. You have to mix them in hot water, let
them stand, soaking the wood surface in the dye solution for
about 20 minutes. Rinse and wipe dry.

You can use this basic recipe,
or use a manufactured stain that is almost a non-color, like
Min-Wax Honey Pecan. Honey Pecan contains only a small amount
of dye and no pigment. To two cups of stain binder you add pigment:
6-8 level tablespoons of wetted pigment or about 5%-10% pigment.
More or less can affect color intensity, but this is where to
start.

Wetted pigment is the consistency
of heavy cream or thin toothpaste. To make wetted pigment, dump
out 6-8 tablespoons of dry pigment and about a tablespoon of
thinner onto a flat surface, one that will not absorb the thinner.
Mix the thinner and pigment into a viscous paste with a putty
knife or a spatula. You can also use Japan Colors as a pigment.
It is already wetted. Japan colors are available at most home
centers, paint stores, and from Woodworker's Supply or www.woodcraft.com

To add the pigment, stir the
stain binder base rapidly while adding blobs of pigment.
This type of stain has to be stirred periodically during use
because the pigment falls to the bottom in a mud-like layer.

Pigmented stains work by allowing
pigment hunks to stick in tiny pores and grain imperfections,
and to be held there by the binder. Sanding beyond 150 or 180
grit prevents these types of stains from working well. These
stains are meant to be applied with a rag or a brush, allowed
to stand for about five minutes. Next, wipe off excess stain.

Pigmented stains tend to highlight
grain, rather than reduce it. Pigmented stains also have an
interesting trait - on some species of wood, like Douglas fir
or hemlock, you may see grain reversal. This is because the
pigment sticks to lighter areas of wood and not to denser dark
areas. After wiping, the dense un-pigmented areas appear lighter
than the surrounding heavily pigmented areas. This creates the
effect of reversing the grain - what was light is now dark, and
what was dark is now light.

Pigments are available as Fresco
Colors from Woodworkers Supply, and www.woodcraft.com.
Bulk amounts of pigments, which are far cheaper, are available
from www.sinopia.com, www.kamapigment.com. Kama
Pigments is in Canada, with significant price advantages for
US consumers, but you have to use a credit card.

Working with create-your-own
stains means that you can create virtually any color, or duplicate
an existing color by mixing different pigments. If you need
to darken the ground color (the color not from the pigment) you
can add wetted oil-soluble dyes to your mix. Oil-soluble dyes
are available from www.woodcraft.com,
Woodworker's Supply, and www.garretwade.com.

Adding Colorants: Pigmented
Wax
You can mix wetted pigments into softened paste wax. Colored
wax is very useful to achieve effects like limed oak (white pigmented
wax), or to highlight oak grain (Van Dyke brown pigment). Consider
using white paste wax to make liming wax, otherwise regular yellow
paste wax works fine. Wood floor centers stock both type of
wax. You can also buy liquid wax, like Liquid Gold, and mix
pigments into it as well. Pigmented liquid wax is extremely
good for eliminating scratches or discolorations on valuable
antiques, because a wax coat is completely reversible and does
no damage.

To soften the hard paste wax,
simply add 1-2 part shaved wax and 1 part turpentine (mineral
spirits doesn't work very well) to a jar. More wax makes the
final softened wax stiffer. I prefer softer wax, so I use 1:1.

Cover the jar and let it sit
for a few days. Slosh the jar once a day. The softened wax
will be the consistency of toothpaste. Add wetted pigment, at
the rate of 4-6 tablespoons or so per cup of softened wax. You
are shooting for about 10% pigment evenly dispersed into the
wax medium. More is a waste of pigment. Less may not provide
enough color.
If kept in a sealed jar, the wax lasts indefinitely. If it becomes
too hard to use, simply shave the wax into solvent, and store
for a while, just like making softened wax.

Apply colored wax just like
regular wax. It works the same way a stain works, the pigment
particles get stuck in tiny pores and are held there by the wax.
The main difference here is that wax is easily removed at any
time with thinner, because it never hardens like the binder in
regular stain.

Shoe wax, like Kiwi brand,
is a pigmented wax, too. It comes in a bunch of colors. In practical
terms, it gives you a chance to play with pigmented wax without
going to a lot of time or expense, because most people have some
in a closet somewhere. Kiwi Bois is the brand of professional
colored wax the Kiwi people make. It comes in much larger cans.
Generally, Kiwi and other shoe waxes are based on shellac wax
- the wax extracted from commercial shellac and hair spray.

Adding Colorants: Shoe Polish
Shoe polish is a great way to make an ebonized finish. Apply
black shoe polish with a rag. Wipe of the excess and let the
surface dry completely. Most brands of shoe polish have both
leather dye and pigment in them.

Adding Colorants: Homemade
Glazing Stain (gilp)
A glazing stain is color that is applied somewhat thickly over
a sealed surface. The color is then gradually removed by wiping,
until the final color is obtained. Glazes are low risk because
they can easily be removed completely, to start over again. Also,
they are useful for simulating dirt accumulations in corners,
or for antiquing distressed surfaces. After the glaze cures,
it has to be locked down, because it is short on binder and will
not resist rubbing off all by itself. The easiest lock down
is to apply two light coats of spray shellac. Zinsser makes spray
shellac from Lowe's and Home Depot. Spray the shellac over the
completely dried (24 hours minimum) glaze. Wait for about two
hours, then apply a heavy coat of clear over the light lock-down
coats. If you plan to rub out a finish, several coats of clear
are needed to have sufficient build to avoid cutting into the
glaze layer during rubout.

The open time on this gilp
is about 3 hours at 70F. So, you need to rub off what you want
or wipe off the entire application with a solvent soaked rag,
all during that time.

Wet the chalk with the turpentine,
then mix the wetted chalk into the linseed oil. Add wetted pigment,
then add the drier last. Turpentine acts to stimulate drying.
If you use mineral spirits instead it will extend the open time
of the glazing stain, but it will increase the overall cure time.

Add the pigment just like you
would for the basic stain recipe. Kept tightly sealed, the glaze
has a shelf life of about 4-5 days. Mix up only as much glaze
as you can use in one or two sessions.